It's the new "It" veggie, the hottest superfood in your grocery store, kale. Celebrities swear by it, the first lady of the United States is planting this Greenleaf with a bitter bite in her garden. Yes, it's cool to eat kale. Darren Rovell explains what all the fuss is about. Reporter: Is there anything hotter than kale? It's in every salad, dominating lettuce bins, popping up in places we could never imagine. Kale is king. Reporter: The kale economy has turned it into a money plant. There are kale smoothies in juice bars. And kale martinis in trendy new York restaurants. There's even kale nail Polish. Gwyneth paltrow has devised a use for kale in recipe after recipe on her blog. First lady Michelle Obama has planted kale in the white house garden. This trend came out of nowhere are. It's incredible how fast this item became popular. Reporter: The demand for this leafy green can be seen here in California's Salinas valley. Also known as the salad bowl of the world. That's where church brothers has doubled the amount of kale they planted in each of the last three years. Look, all you can see, as far as you can see. That's how much people like it. Honestly, I can't see the end of this. Reporter: Whole foods sells more than 22,000 bunches of kale per day in its stores. And mentions of kale on U.S. Restaurant men use over the last two years are up 233%. This is essentially what was on the outside of the salad bar. Exactly. The real stuff was here. And so now it's gone like this. And now it's -- now this is the salad. It's climbed from the darkest area into the salad bar, I think that's right. Reporter: That role reversal helped by culinary shows spending time extolling the virtues of the cruciferous wonder. I love it because it's delicious raw, delicious cooked. Reporter: Is it a fad? What's the shelf life of a leaf that takes like, well, a leaf? Compared to a lettuce? Or a spinach? It really doesn't have that much flavor. Reporter: It doesn't taste the greatest. The texture isn't the greatest. But is that part of the whole marketing of it? Trust me, if there's a way for me to make this green kale taste any better? I would do it. Reporter: Its popularity has elicited haters. Comedian jiff gafigan -- Can we stop with the kale propaganda? That stuff tastes like bug spray. Reporter: The lovers of kale prevail. Sprouting up innovative new products while one of the original twists on kale, kale chips, continues to grow. It's just air dried. Reporter: Brad gruno is riding the kale wave and making it taste better. We have five flavors starting with naked, the vampire killer. Put garlic in there, what are we going to call it? Vampire killer! Then we have the nasty hot. Then we have the nacho. Then we have the pinot kale-ada. Reporter: Brad's raw foods will pull in an estimated $20 million this year. 70% of that from kale products. It is the color of money. Reporter: Make no mistake, kale's greatest marketing ploy is how good it might be for you. This is the highest nutrient dense leafy green they sell in a grocery store. It's amazing how it blew up. Do you grow this yourself? Reporter: Four years ago, long before seemingly everyone knew what kale was, gruno was selling bags of kale chips at this farmer's market in bucks county, Pennsylvania. I had little bowls and just give it away all the time, taste it, taste it. Saying the same story over and over again. Reporter: When people bought it for the price he was selling it for, he knew he had a winner. I love your chips. Thank you. Here I am selling a bag of chips for seven bucks. Know what I mean? People thought I was crazy. You know how many people said, brad, it's the craziest thing you ever did. Then look what happened to my business. Reporter: He's now using 40,000 pounds of kale a week. If you haven't sunk your teeth into kale yet, he has something up his sleeve that might lure you in. When is chocolate kale come snlg. This year. It? Holiday chocolate with coffee, like a coffee taste on the kale. Reporter: Take that, arugula. I'm Darren Rovell for "Nightline" in bucks county, Pennsylvania.

This transcript has been automatically generated and may not be 100% accurate.

Now Playing: Friends, families mourn Florida high school shooting victims

Now Playing: 'Black Panther' stars on the power of telling a story from a black perspective

Now Playing: Drake claims to give away almost $1 million in new music video